#include<stdio.h>
int main()
{
    int start=1,end=100,i;
    int tot=0; //(1)
    i=start;
    while(i<=end){
        if(i%2==0)
            tot=tot+1;
        i=i+1;
    }
    printf("%d\n",tot);

    return 0;
}
